"Rare" eludes me as an interesting quality. I have several one-off Gibsons and really my reaction is, "so what?" They're just custom shop creations. Carvin/Kiesel guitars are all one-offs (thus "rare") and I suppose you could apply that to a lot of Trussart, Suhr, Anderson, etc. guitars that no one really wanted to duplicate.

"Rare" can also indicate production guitars that were simply undesirable or unsuccessful in their time. And if the "rare" part is just a paint job, what the hell?

I always thought it was kind of funny that Gibson bothered to get rid of the outer poles of the pickups, even going so far as to make special stampings on its HB covers. Like it wouldn't have looked weird to just use regular pickups, especially on those P-90s with the big pearl dots glued into the covers -- like, those stand out worse than the pole screws, lol.